This project seeks to define methods and mechanisms for the bioelectric control of cell function. The approach is based upon the analysis of potential dependent phenomena at cell surfaces involving interactions of charged species such as divalent cations and hormones. Inductively-coupled electromagnetic fields are utilized to provide a variety of bioelectric perturbation with information content chosen via the above. Assessment of this approach is made through in vitro studies of protein synthesis and 45Ca release by osteogenic and chondrogenic cells, and of dynamic Na ion transport in the toad bladder membrane, as well as by in vivo studies of fracture healing in a rat radial osteotomy model. Primary emphasis is focused upon the elaboration of induced current pulse characteristics, e.g. shape, frequency content, amplitude spectrum, and repetition rate which have biologic significance during bone formation and repair. Quantitative evaluations are obtained via impedance, radioactive labelling, radiographic, histological and mechanical testing techniques. BIBLIOGRAPHIC REFERENCE: Zengo, A.N., Bassett, C.A.L., Prountzos, G., Pawluk, R.J. and Pilla, A.A., In Vivo Effects of Direct Current in the Mandible. J. Dent. Res. 55: 383-390, 1976.